PreparED Study Materials
ST 521: ST 521
School: North Carolina State University
Number of Notes and Study Guides Available: 2
Notes
Videos
Brand X vs. Brand Y: 95% Confidence in Voltage Difference
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
Compare the voltages of Brand X and Brand Y batteries using statistical analysis. Learn how to determine a 95% confidence interval for their mean differences. Understand the process from data collection to interpretation of results.
Battery Lifetimes: Mean, Variance & Standard Deviation
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
Discover the nuances of analyzing battery lifetime data through mean, variance, and standard deviation computations. Using class boundaries, midpoints, and frequencies, gain insights into the dispersion of battery lifespans and the average deviation from the mean.
Car Theft Rates: Does Your Car Type Influence Risk?
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
Explore the relationship between specific car types and their theft rates. This video assesses correlations between car models like the Honda Accord, Toyota Camry, and others, emphasizing the difference between correlation and causation.
Understanding Delaware's Income Distribution: A Statistical Look
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
Analyze Delaware's per capita annual income using statistical methods. Understand the probabilities associated with various income levels for a sample of state residents. Learn to use the Z score formula for such evaluations.
Evaluating Tornado Length Claims: A Statistical Breakdown
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
Explore a statistical approach to analyze the claim about average tornado lengths. Understand the nuances of hypothesis testing, from setting null and alternative hypotheses to interpreting P-values. Witness a comprehensive breakdown of the evidence from a sample of 500 tornadoes.
Pet Phone Calls: Validating a 37% Claim with Z-test
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
Explore a claim from the American Animal Hospital Association that 37% of pet owners communicate with their pets over the phone. Through hypothesis testing and a z-test, evaluate a skeptical veterinarian's doubts. Conclusions shed light on pet owners' unique communication habits.

















